Utilising Smartphones for Photography

By Clint Singh / 20 Oct 2020

Photographer Clint Singh outlines solutions for the common mistakes aesthetic clinics make taking before and after images on their smartphones

Aesthetic clinics typically document their work by showcasing before and after imagery on their social media channels and websites. However, aesthetic practitioners are medical professionals and not photographers, meaning they often lack the knowledge, space or equipment to take these images professionally. Although professional cameras can achieve good photo outcomes, they can be expensive and may require space in your clinic which you might not have. The easiest and quickest solution is to use smartphone photography. Although these devices can produce high-quality images given the right environment, a quick look on social media will yield an array of shocking before and after images. These images are of different exposures, colour and sizes, making it difficult to see results.

Why are before and after images taken on smartphones sometimes so drastically different from each other? If practitioners try taking a photograph of a patient in the same place at different times of the day, there will be a significant alteration in colour, exposure and image quality, caused by changing ambient light. At times, the disparity can be so drastic that it makes it difficult to see which procedure has been carried out and the effects of that procedure. Inconsistency is exacerbated further by the lack of official guidance outlining patient photography in aesthetics.1

To understand how to take smartphone images in the most effective way possible, it is important to first have a basic knowledge of photography, the science of light and how to use the two together. Most important within this equation is consistency with both lighting sources and the distances and angles from the patient.

Lighting environments

Cameras on smartphones work in automatic mode, so depending on the colour and strength of the light entering the lens, the sensors will try to adjust your image based on a pre-set algorithm. If the light in the room is in any way influenced by light from outside the room, the colour temperature and exposure of the resulting image will be altered.

There are settings that we need to take into account in this changing environment:

1) Shutter speed: responsible for the sharpness of the image

2) Aperture: responsible for which part of the image is in focus

3) ISO: controls the sensitivity of the camera sensor

4) Colour temperature: controls how warm or cool your image appears2

The aperture settings on smartphones are fixed, so depending on the environment you provide, your smartphone (which is in auto by default) will try to correctly expose the image with shutter speed and ISO, and adjust the colour temperature automatically for the final image.

So, unless we can control the environment, we are at the mercy of the sensors and the automatic settings to give us accurate results for our documentation. And whilst we cannot manually control the settings on these devices, we can influence them by providing a stable lighting environment so that the camera’s shutter speed, ISO and the resulting colour temperature are identical between sessions.

Solutions

So how can practitioners provide a stable lighting environment in clinics? Firstly, there needs to be a dedicated constant light source. LED lighting provides this consistent source, but clinics should avoid anything on a tripod which has height, angle and tilt adjustments, unless they can leave it exactly as it is between photographs, as practitioners will need to replicate this later and there are too many variables to control accurately.

To make sure we get our lighting right, let’s take a quick look at the inverse square law of light  which describes the intensity of light at different distances from a light source. If the light source is twice the distance from the subject, the illumination on the subject will be one quarter of the intensity based on this law.3 So we can’t place the subject at roughly the same distance from the light between sessions, as it has to be exactly the same, or the subject will be at completely different levels of illumination between sessions.

In order to create a stable lighting environment in clinics without specialised equipment, practitioners firstly have to use a room that is shielded from any outside light, so an inner room without windows will be the best choice, or at worst, close all curtains and blinds.

In my experience, the ideal light source would be two upright LED lights, tall enough to illuminate the area on the patient you want to photograph without making height adjustments. They can be secured to a heavy metal base and marked so that they are always at 45 degrees to the patient when moved, which can be done using the octagonal floor marker below (Figure 1).

Figure 1: Example of a person lit with two upright LED lights photographed on a smartphone

Existing overhead lights may provide a reasonable light source, but they can create shadows from above. Practitioners will also have to take note of the colour temperature of this light and may have to experiment with different types of lamps or bulbs, until they have an acceptable colour to the images.

The ideal positioning of the subject in the room will depend on the size of the room and where overhead lights are located. But once this area has been found, it should remain the same for all patients. To keep your angles consistent, you can use an octagonal marker on the floor which will not only keep the patient in the same position, but will also let you document your patient at every 45 degree angle to the camera (Figure 4). The following tips will help to find the ideal position:

Don’t place your patient directly under the ceiling lamps – this will throw very strong shadows onto the patient and the camera will also struggle to expose the hotspots which the light from above will throw (Figure 2)

· Use light that has been reflected off walls – the brighter the room the better (Figure 3) – and always use the same room for your before and after images to avoid changing lighting conditions

Figure 2: An overhead downlight throwing harsh shadows on a patient and the colour temperature of the lamp is too warm

Figure 3: The same patient lit using overhead LED ceiling office lights reflected off walls. The patient is positioned between two of the overhead lights; the colour temperature of the lamps are much cooler and the image is well exposed

Consistency is key

Consistency with before and after documentation is crucial and there are a number of factors that need to be considered. Once clinics have a stable lighting environment, they will then need to address angles, colours and distances.

Angles

As discussed above, to keep your angles consistent, you can use an octagonal marker on the floor which will let you document your patient at every 45 degrees to the camera (Figure 4). While this will keep the patient’s body in the same position between sessions, if you are doing headshots, using additional markers that correspond with the octagonal floor marker at eye level will help to keep the patient’s head position consistent. The additional markers should be placed on walls at eye level around the room and correspond to the numbers on the floor marker.

Figure 4: An octagonal floor marker to keep your patient in the same position between sessions

Colours

When smartphones take an image, the sensors pick up reflected light and try to calculate appropriate colour temperature.4 Whatever light that falls on the camera’s sensor will be taken into account in this calculation. Not only is keeping this colour temperature and environment consistency important, but this calculation will have an impact on skin tones too. In my experience, to minimise the impact of vastly differing skin tones between shoots, use a white background, or a white wall if available. This is because the camera’s auto settings work by taking a reading of the entire scene, including the background. The background heavily influences the colour of the resulting image. While using a black background might give a decent image, as can be seen in Figure 6, it can result in the image being oversaturated. Use a cape to cover the subject’s clothes for headshots, so the field of vision of the camera between sessions is limited to the patient’s face. If you are documenting the abdominal area or lower body, ensure the patient uses the same garments between sessions.

Figure 5: Patient standing in front of a white background

//FIGURE 6 CAPTION// Figure 6: Patient standing in front of a black background. Both images were taken using the same smartphone, using the same upright LED lights, and at the same distance and angle.

Distances

Clinics want to ensure that the proportional size of your subject in both images is consistent, which can be done by maintaining the same distance between the smartphone and the patient. If the octagonal floor marker is used, the patient should be in the same position between sessions, but an additional marker should be used (tape will do) on the floor to keep the smartphone in the same position between sessions. Also, ensure the camera isn’t too close, ideally at around 60cm from the subject, as smartphone cameras suffer from very noticeable perspective distortion. Keep the smartphone level to the area on the subject you are photographing, which will give you consistency even if you have staff of different heights.

Conclusion

Given the right environment, modern smartphones can produce accurate images to document patient procedures. Once stable lighting has been established to keep the exposure and colour temperature consistent, it is possible to implement a set of standardised protocols to maintain consistency between sessions for angles and distance, ensuring accurate and precise documentation.

Smartphones’ ease of use and simple point and shoot capabilities, combined with industry-established patient management apps and the right lighting conditions, make them an ideal tool to capture before and after images accurately, while maximising your time with your patients. Remember, consistency is key!

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